PHOENICS News... or contact Stefano Malavasi (e-mail: [email protected]) Figure 4. A...
Transcript of PHOENICS News... or contact Stefano Malavasi (e-mail: [email protected]) Figure 4. A...
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Table of Contents:
Title Page
PHOENICS for teaching at Politecnico di Milano 2
CFD simulation of wind flows around a new
building structure using the Flair-EFS subset of
PHOENICS-Flair
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RhinoCFD Presented in Helsinki 7
PHOENICS 2019 8
CHAM Announcements 8
Contact Us 8
Concentration Heat and Momentum Limited, Bakery House, 40 High Street, Wimbledon, London SW19 5AU, UK
Telephone: 020 8947 7651 Fax: 020 8879 3497
E-mail: [email protected], Web site: http://www.cham.co.uk
News PHOENICS News
Winter 2018 /
2019
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PHOENICS for teaching at Politecnico di Milano: the new course “Laboratory of Fluid Mechanics:
the Green Valve case study” by Gianandrea Vittorio Messa, Politecnico di Milano.
The FluidLab research group at the department of Civil and Environmental Engineering of Politecnico di Milano
has long-term experience in the use of PHOENICS for teaching activities. Since 2010, PHOENICS has been used
within the “Fluid Labs” course for the MSc in Civil and Mathematical Engineering, taught by Professors Stefano
Malavasi and Francesco Ballio. The students are given advanced knowledge of selected topics in fluid mechanics,
such as the boundary layer theory of internal flows and the problem of fluid-structure interaction, and they
apply the theoretical concepts by performing laboratory experiments and numerical simulations on different
benchmark cases (developing turbulent channel flow, pipe orifice flow, and flow around a prismatic object.)
In the present academic
year, a new course
involving PHOENICS was
established; namely the
“Laboratory of Fluid
Mechanics: the Green
Valve case study”, taught
by Dr Gianandrea Vittorio
Messa. To understand the
framework in which the
course was developed, it
should be borne in mind that Politecnico di Milano is strongly encouraging innovative methods in teaching and
learning. The “Passion in Action” programme includes open participation teaching activities offered to students
to support the development of transversal, soft and social skills and to encourage/facilitate students in enriching
their personal, cultural and professional experience. Dr Messa, already in charge of “Fluid Mechanics” for final-
Figure 1. The students and the teacher of the Laboratory.
Figure 2. The Green Valve concept.
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year BSc students in Mechanical Engineering, organized the Laboratory as part of the above programme. His
goal was to provide students with an overview of the problem-solving approaches in industrial fluid mechanics,
namely laboratory testing, concentrated parameter modelling, and Computational Fluid Dynamics (CFD). The
initiative, held in the Piacenza Campus of Politecnico di Milano, involved some 50 participants.
Students were given a case study that was both innovative and complex from the fluid dynamic and modelling
points of view. This is the Green Valve, a device for the control and recovery of energy patented by Politecnico
di Milano (DICA.15.002.A; inventor: Stefano Malavasi). In its original configuration, the Green Valve consists of
a ball valve with a horizontal shaft turbine, which allows recovering a fraction of the energy dissipated in the
flow control process (Figure. 2). In turn, the recovered energy can be used for various purposes, such as feeding
monitoring systems to control the quality of the flowing water or the supply of power to the actuator;
alternatively, it may simply be connected to the utility grid (Figure. 3).
In the part of the Laboratory dedicated to CFD, students were given an engineering-oriented overview of this
approach, (thus becoming aware of possible sources of inaccuracy), and they were shown best practices and
guidelines for attaining reliable numerical predictions. Students became familiar with the basic concepts of the
numerical consistency of the solution (eg, grid-independence), sensitivity of the estimates upon modelling
parameters, and experimental validation. Since reproducing the Green Valve would have required an excessive
calculation time, only a 2D slice of the device with the blades in fixed positions was simulated in class.
Students were aware that this simplified model would not completely represent the actual flow (Figure. 4). They
worked in small groups, which were assigned different input data in terms of combinations of valve opening,
position of the blades, and inlet velocity. After developing the CFD setup and verifying its consistency, they used
the 2D solution to gather a rough estimation of the flow coefficient of the Green Valve under the same working
conditions. The numerical estimates provided by some groups are reported in Figure. 5, together with those
calculated by PhD students Qi Yang and Yongo Wang from the FluidLab group. The results compare quite well
with experimental data collected in the Hydraulic Laboratory of Politecnico di Milano.
Figure 3. Possible uses of the recovered energy.
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Figure 5. The flow coefficient of the Green Valve, as estimated by the students from the 2D model solution,
and the experimentally measured values collected in the Hydraulic Laboratory.
The first-year experience of the course has definitely proven successful. The number of attenders was
significantly greater than was expected, and they all provided a good evaluation of the course. The students
faced, for the first time, different problem-solving techniques used in engineering practice, and they were
introduced to PHOENICS as their first CFD code. The positive feedback encourages the teacher to repeat the
initiative in the future.
Post Script: The numerical results shown in Figure 4 and 5 were obtained by PhD students Qi Yang and Yongo
Wang from the FluidLab group and by the following attenders of the course: Emilio Giorgio Carlo Azzoni, Matteo
Bertelli, Lorenzo Cenotti, Marco Dante Clerici, Mattia Libiani, Raffaele Marchetti, Lorenzo Palermino, Edison
Shehu, Ermes Zamboni. For more information about the Green Valve, please refer to the website
www.fluidlab.polimi.it or contact Stefano Malavasi (e-mail: [email protected])
Figure 4. A typical velocity field obtained from PHOENICS.
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CFD Simulation of Wind Flows Around a New Building Structure Using the Flair-EFS Subset of
PHOENICS-Flair 2018
By Timothy Brauner, CHAM & Susana Baptista, Agri-Pro Ambiente
Portuguese-based environmental consulting company, Agri-Pro Ambiente, approached CHAM for CFD software
to model the external built environment, resulting in procurement of the Flair-EFS (External Flow Simulation)
subset of the PHOENICS/Flair package. The following describes a demonstration case of Flair-EFS applied to a
proposed quay-side development in Macau.
Google Maps image of
the Macau Quay and
CFD model (ignoring
reclaimed land area to
the right.) Proposed
new structure is
shown in red.
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CHAM engineers created a 3D representation of the region of interest based upon 2D topology information
supplied by the client, combined with the proposed new structure and its surrounding buildings, within the Flair-
EFS user environment. The prevailing wind (for this particular demonstration case only the North direction was
used) and environmental conditions were then added.
Flair-EFS creates a suitable computational mesh automatically; the building of interest is sited at the centre of
the domain with all else placed around it on the assumption that those objects are centred relative to the
building of interest. It is straightforward to use the centre of the building of interest as the datum point for all
objects; eg having surrounding information in equal distances in all directions away from the building centre.
Multiple data collection points were generated at pedestrian level in the region, in line with customer
requirements, with and without the new structure in situ. A macro file was created - activated from Flair-EFS in
its post-processing mode - to extract simulation data at the location of the points specified.
The customer’s objective was to assess wind velocity at various locations, under varying environmental
conditions, in order to investigate the possibility of any adverse local conditions - in particular those arising at
pedestrian level - that may result from the construction of the new building.
“This simulation confirmed a preliminary assessment made by AgriPro Ambiente, and due to the ease of use of
the software, the excellent graphic results obtained and the achievement of the desired results, this software
was acquired by this company and has already been used in two subsequent projects, with formal approval by
our clients.”
www.agriproambiente.pt
Flair-EFS is a reduced-cost subset of CHAM’s PHOENICS/Flair module for the simulation of the built environment – see: http://www.cham.co.uk/_docs/FLAIR_BROCHURE2015_PLSWBS.pdf. Contact [email protected] for further information.
Wind velocity contours and vectors. Proposed new structure shown in red.
Below & right: Surface pressure on new building and Pedestrian level measurement points
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CHAM’s Andrew Carmichael presented the company’s
RhinoCFD Software (powered by PHOENICS) at the Rhino User
Meeting held by McNeel in Helsinki in January this year. The
presentation took the form of a case study based on the
modelling of a Trombe Wall which had been prepared at
CHAM.
It seemed that, though many of those at the presentation were
from institutions relating to the built environment, many did
not seem to be aware of the Trombe Wall, and what it does.
Time was limited for Exhibitors so there was no opportunity to
take questions after the presentation but it would seem that
fields of particular interest included the heat transfer element
of Trombe Wall activity, the use, and effect, of hedges diverting
flow away from the building and thus reducing the cooling
effect of wind and mention of comfort indices.
Those visiting CHAM’s stand (pictured left) during the day were
able to be shown what RhinoCFD could do and take
information away with them. Visitors were positive about the
fact that results modelled using PHOENICS could be displayed
directly in Rhino which saved the necessity of using several
pieces of software to obtain a finished result. Positive
comments were also made regarding convergence coming up
automatically and being colour coded for ease of
understanding. There was a favourable ease of use comparison
and questions were asked regarding integration with
Grasshopper and the Ladybug Tools environment. The speed
with which the meshing system could be set up when
geometry changed had a positive impact given that user
experience (as is normal with unstructured meshes), indicated
that re-meshing involved expenditure in time and cost.
Presentation of RhinoCFD (Powered by PHOENICS) at the January 2019 Rhino User Meeting in Helsinki
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A Memorial bench has been placed on Wimbledon Common in memory of our founder, Professor Brian Spalding.
Should you require any further information on any of our offered products or services, please give us a call
on +44 (20) 8947 7651. Alternatively, you can email us on [email protected]
Our website can be viewed at www.CHAM.co.uk and we are on the following social media:
Concentration Heat and Momentum Limited
Bakery House
40 High street
Wimbledon Village
London SW19 5AU, England.
Contact Us:
CHAM Announcement
Work in currently in hand completing the next upgrade of PHOENICS. The code is scheduled to be available by
end March. It will be supplied to all new customers from the beginning of April and also to all, maintained, users
who wish to upgrade.
Full information on new features in PHOENICS 2019 will be available on our website and in the next issue of the
Newsletter (to be distributed in April/May this year).
For advance information or to order an upgrade please contact [email protected].
PHOENICS 2019